Pressure to improve quality and lower cost of health cre has created the need to understand the effectiveness of medical interventions, such as gastrointestinal (GI) endoscopy. Despite widespread use of endoscopic procedures, very little is known about endoscopic practice patterns and patient outcomes in community-based settings. The ideal method for studying endoscopic procedures is to go directly to the source: the endoscopy report. With the advent of computerized databases, it is now possible to generate endoscopic reports while simultaneously creating a data file. We have developed a network of GI specialists in diverse practice settings who utilize a common computerized endoscopic report generator. Endoscopic data from these Clinical Affiliates is transmitted electronically to a centralized data repository and merged with data from multiple Clinical Affiliates for analysis. These merged data can then be used to examine practice patterns and address important research questions. Based on extensive experience in building a clinical network for endoscopic research our group is unique able to meet the requirements stipulated in the current proposal. The primary goal of this proposal is to use the existing endoscopic database to acquire information that will improve the quality of clinical practice in gastroenterology. The specific aims of this proposal are to use the endoscopic database to: . Perform descriptive analyses of utilization, frequency and severity of endoscopic findings, practice patterns, practice variation (geographic region, type of clinical practice), and patient demographics (age, gender, race). . Use descriptive analyses to form the basis for developing hypotheses and risk stratification. . Observe the natural history of chronic GI diseases, and determine appropriate intervals for surveillance. . Determine the success and effectiveness of endoscopic therapies and new endoscopic innovations. . Determine the impact of endoscopic diagnoses and therapies on patient outcomes. . Evaluate the frequency of endoscopic complications, and risk factors for complications. . Use the database for specific research projects and to create patient registries for clinical trials.